1. Field of the Invention
This invention relates to the field of implantable percutaneous devices and more particularly to the field of devices used in dispensing insulin into the peritoneal cavity.
2. Description of the Prior Art
Diabetes mellitus is a chronic systemic disease afflicting about 10 million Americans. Diabetes is currently the third leading cause of death in the United States and is the principal cause of blindness among adults. It is believed that improved blood glucose control will reduce the longterm complications of diabetes. Currently, diabetes is controlled daily by single or multiple subcutaneous injections of combinations of regular and long-acting insulins. Subcutaneous injections tend to prevent severe hyperglycemia and offering advantages over intramuscular injection of insulin thereby permitting the insulin-dependent diabetic to survive.
Since a normal pancreas secretes all its insulin into the portal vein, delivery of insulin into this site would be more "physiologic." The peritoneum has been suggested as an insulin delivery site.
Intro-peritoneal delivery of insulin allows insulinization of the liver without peripheral hyperinsulinemia, rapid and predictable insulin absorption and eliminates blood clotting at the tip of the delivery catheter. Injection of insulin through a peritoneal implant mimics the physiologic route of insulin released by the pancreas and avoids the disadvantages inherent in intramuscular delivery of insulin.
A second contemplated use for the device of the invention is in connection with peritoneal dialysis. Peritoneal dialysis has been accomplished to date by means of a flexible catheter which is implemented so as to pass directly through the skin and peritoneal wall into the peritoneal cavity. A recent detailed review of devices associated with peritoneal dialysis may be found in Ward et al, "Investigation of the Risks and Hazards with Devices Associated with Peritoneal Dialysis (Including Intermittent Peritoneal Dialysis and Continuous Ambulatory Peritoneal Dialysis) and Sorbent Regenerated Dialysate Delivery Systems," revised draft report for FDA contract No. 223-81-5001 (June, 1982).
Despite extensive protocols for maintaining sterility, infection frequently occurs as a result of peritoneal dialysis. The most common infection pathway is through the interior of the catheter but exit site infection caused by bacteria invasion along the exterior surfaces of the catheter occurs as well.
Improvements in prior art peritoneal dialysis implants are described in co-pending applications Ser. No. 314,569, filed Oct. 26, 1981; Ser. No. 410,365, filed August 23, 1982, and U.S. Pat. No. 4,417,888 all of which have a common assignee with the present application. The improvements of these prior applications comprise rigid tubular percutaneous devices implanted through the skin to which a catheter member is affixed subcutaneously. Access to the peritoneum in these devices is accomplished through a sterile needle assembly which enters a septum.
Co-pending applications Ser. Nos. 314,569; 410,365 and U.S. Pat. 4,417,888 are incorporated herein by reference to illustrate the state of the art in peritoneal dialysis implants.
Robert L. Stephen identifies an intra-peritoneal insulin access device in "Stabilization and Improvement of Renal Function in Diabetic Nephropathy" in 1 Diabetic Nephropathy 8 (November, 1982). The device shown therein consists of a polyurethane bowl and stem which is completely embedded within and under the skin such that an epidermal layer covers the entire surface. Such a device still requires the passage of a needle through body tissue to enter the device.